This invention relates to methods of making a wall on the peripheral wall surface of a tunnel. More particularly, this invention relates to a method of making a primary covering wall on the peripheral wall surface of the tunnel made by a shield type excavator. According to the method, the primary covering wall may be stabilized immediately after the wall is formed.
In a typical tunnel making method, a tunnel excavating system employs a shield type excavator. A shield of a steel-made cylinder of the excavator is driven into the ground at the tunnel face and a rotary cutter head provided in the front portion of the excavator is rotated to excavate the ground and bore the tunnel. While excavating the tunnel with such a shield type excavator, it is required to form a covering wall against the peripheral wall surface of the tunnel, which extends behind the excavator as the excavator is advanced.